Failure modes and FEM analysis of Conductive Anodic Filament resistance during high-frequency electromagnetic of PCB

2012 ◽  
Author(s):  
You- Yi Chen ◽  
Mei-Ling Wu
Keyword(s):  
High Frequency ◽  
Failure Modes ◽  
Fem Analysis ◽  
Conductive Anodic Filament

scholarly journals Crack-Length Estimation for Structural Health Monitoring Using the High-Frequency Resonances Excited by the Energy Release during Fatigue-Crack Growth

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4221
Author(s):  
Roshan Joseph ◽  
Hanfei Mei ◽  
Asaad Migot ◽  
Victor Giurgiutiu
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Length ◽  
Crack Growth ◽  
Health Monitoring ◽  
Acoustic Waves ◽  
High Frequency ◽  
Fem Analysis ◽  
Signal Frequency ◽  
Propagation Pattern

Acoustic waves are widely used in structural health monitoring (SHM) for detecting fatigue cracking. The strain energy released when a fatigue crack advances has the effect of exciting acoustic waves, which travel through the structures and are picked up by the sensors. Piezoelectric wafer active sensors (PWAS) can effectively sense acoustic waves due to fatigue-crack growth. Conventional acoustic-wave passive SHM, which relies on counting the number of acoustic events, cannot precisely estimate the crack length. In the present research, a novel method for estimating the crack length was proposed based on the high-frequency resonances excited in the crack by the energy released when a crack advances. In this method, a PWAS sensor was used to sense the acoustic wave signal and predict the length of the crack that generated the acoustic event. First, FEM analysis was undertaken of acoustic waves generated due to a fatigue-crack growth event on an aluminum-2024 plate. The FEM analysis was used to predict the wave propagation pattern and the acoustic signal received by the PWAS mounted at a distance of 25 mm from the crack. The analysis was carried out for crack lengths of 4 and 8 mm. The presence of the crack produced scattering of the waves generated at the crack tip; this phenomenon was observable in the wave propagation pattern and in the acoustic signals recorded at the PWAS. A study of the signal frequency spectrum revealed peaks and valleys in the spectrum that changed in frequency and amplitude as the crack length was changed from 4 to 8 mm. The number of peaks and valleys was observed to increase as the crack length increased. We suggest this peak–valley pattern in the signal frequency spectrum can be used to determine the crack length from the acoustic signal alone. An experimental investigation was performed to record the acoustic signals in crack lengths of 4 and 8 mm, and the results were found to match well with the FEM predictions.

scholarly journals Gaining Insights in Loading Events for Wind Turbine Drivetrain Prognostics

2020 ◽  
Author(s):  
Pieter-Jan Daems ◽  
Y. Guo ◽  
S. Sheng ◽  
C. Peeters ◽  
P. Guillaume ◽  
...  
Keyword(s):  
High Frequency ◽  
Failure Modes ◽  
Measurement Data ◽  
Wind Farms ◽  
Frequency Measurement ◽  
Operating Conditions ◽  
Failure Data ◽  
The World ◽  
Operations And Maintenance ◽  
History Of

Abstract Wind energy is one of the largest sources of renewable energy in the world. To further reduce the operations and maintenance (O&M) costs of wind farms, it is essential to be able to accurately pinpoint the root causes of different failure modes of interest. An example of such a failure mode that is not yet fully understood is white etching cracks (WEC). This can cause the bearing lifetime to be reduced to 5–10% of its design value. Multiple hypotheses are available in literature concerning its cause. To be able to validate or disprove these hypotheses, it is essential to have historic high-frequency measurement data (e.g., load and vibration levels) available. In time, this will allow linking to the history of the turbine operating data with failure data. This paper discusses the dynamic loading on the turbine during certain events (e.g., emergency stops, run-ups, and during normal operating conditions). By combining the number of specific events that each turbine has seen with the severity of each event, it becomes possible to assess which turbines are most likely to show signs of damage.

Failure modes and FEM analysis of power electronic packaging

2002 ◽  
Vol 38 (7) ◽  
pp. 601-612 ◽  
Author(s):  
Hua Ye ◽  
Minghui Lin ◽  
Cemal Basaran
Keyword(s):  
Electronic Packaging ◽  
Failure Modes ◽  
Fem Analysis ◽  
Power Electronic

The Experimental Study on Wear Performance of Brazed Diamond Grits

2007 ◽  
Vol 359-360 ◽  
pp. 28-32 ◽  
Author(s):  
Yan Chen ◽  
Hong Jun Xu ◽  
Yu Can Fu
Keyword(s):  
Single Crystal ◽  
High Frequency ◽  
Failure Modes ◽  
Wear Test ◽  
Wear Performance ◽  
Single Crystal Diamond ◽  
High Frequency Induction Brazing ◽  
Test Result ◽  
Better Than ◽  
High Frequency Induction

The wear resistance samples of brazed single crystal diamond with Ni-Cr filler alloy were prepared, using high frequency induction brazing and vacuum brazing methods. By wear test of brazed single crystal diamond, the wear performance of the samples with different brazing processes was studied. The test result indicates that the wear performance of the high frequency induction brazed diamond samples is better than that of the vacuum brazed diamond samples. Because of different brazing processes, the wearing pattern of diamond varied; the wear course of the vacuum brazed diamond samples in the initial wear period were abnormal and the failure modes is different.

scholarly journals Application of High-Frequency Leakage Current Model for Characterizing Failure Modes in Digital Logic Gates

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2906
Author(s):  
Zahra Abedi ◽  
Sameer Hemmady ◽  
Thomas Antonsen ◽  
Edl Schamiloglu ◽  
Payman Zarkesh-Ha
Keyword(s):  
Predictive Model ◽  
Leakage Current ◽  
Electromagnetic Interference ◽  
High Frequency ◽  
Failure Modes ◽  
Current Model ◽  
Measurement Data ◽  
Logic Gates ◽  
Cmos Inverter ◽  
The Impact

In this paper, a predictive model is developed to characterize the impact of high-frequency electromagnetic interference (EMI) on the leakage current of CMOS integrated circuits. It is shown that the frequency dependence can be easily described by a transfer function that depends only on a few dominant parasitic elements. The developed analytical model is successfully compared against measurement data from devices fabricated using 180 nm, 130 nm, and 65 nm standard CMOS processes through TSMC. Based on the predictive model, the impact of EMI on leakage current in a CMOS inverter is reduced by increasing the frequency from 10 MHz to 4 GHz.

Analytical and Numerical Evaluation of the Cyclic Yield Area Criteria for Shakedown Requirements

2002 ◽  
Author(s):  
Isoharu Nishiguchi ◽  
Asao Okamoto ◽  
Norimichi Yamashita ◽  
Mitsuru Aoki
Keyword(s):  
Pressure Vessel ◽  
Numerical Evaluation ◽  
Failure Modes ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Stress Evaluation ◽  
Division 1 ◽  
Section Viii ◽  
Division 2 ◽  
Stress Criteria

The rules in codes such as the ASME Boiler and Pressure Vessel Code Section III Division 1 and Section VIII Division 2, provide the concept of stress categorization to prevent inelastic failure modes based on the elastic analyses. The categorization of the stresses obtained by the FEM analysis, however, is not always clear and the Three Dimensional FEM Stress Evaluation in JPVRC (TDF committee) has been developed alternative criteria to dispense with the stress categorization. As for the evaluation of the primary plus secondary stress, criteria based on the concept of the Cyclic Yield Area (CYA) have been developed. In this paper, the recent results obtained in the committee are summarized to evaluate the validity and the usability of the criteria.

scholarly journals Shear Buckling of Plate Girders with Corrugated Web Restrained by End Stiffeners

2018 ◽  
Author(s):  
Witold Basiński
Keyword(s):  
Failure Modes ◽  
Numerical Models ◽  
Fem Analysis ◽  
Sine Wave ◽  
Experimental Investigations ◽  
Plate Girders ◽  
Buckling Resistance ◽  
Corrugated Web ◽  
Shear Buckling ◽  
Interactive Buckling

The study reports the investigations into the effect produced by flexural stiffness of end stiffeners on the design buckling resistance of the sine wave webs of girders. Experimental investigations were concerned with load displacement paths in sinusoidally corrugated web girders, composed of structural items and made to the full scale . The phenomena occurring in experimental investigations were represented using the Finite Element Method. In numerical models based on FEM analysis, the same failure modes of webs that were found in experimental investigations into corrugated web girders were accounted for. FEM numerical analysis was performed for girder models with webs 500, 1000, 1250 and 1500 mm in height, made of corrugated sheet metal 2, 2.5 and 3 mm in thickness. On the basis of laboratory tests and FEM analysis, a new method for estimating design shear buckling resistance for girders with semirigid and rigid end stiffeners was proposed. The method relies on the determination of interactive buckling resistance. The solution presented in this study was compared with formulas currently used for buckling resistance estimation. It was shown that the use of girder rigid end stiffeners produces in increase in shear buckling resistance up to 11%. Conclusions were drawn and recommendations were made with respect to the sizing of sine wave corrugated web girders with semirigid and rigid end stiffeners.

scholarly journals Design Analysis of High Frequency Linear Transformer with Ārtap Framework

2021 ◽  
Author(s):  
Tamás Orosz ◽  
Mariusz Stępień ◽  
Peter Poór
Keyword(s):  
High Frequency ◽  
Mass Density ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Design Analysis ◽  
Leakage Inductance ◽  
Design Variables ◽  
Calculation Results ◽  
Transformer Design ◽  
2D And 3D

This paper presents the design and a design analysis of a coaxial, linear transformer. This is a novel high frequency transformer concept for energy conversion. The examined transformer was designed for 1 MHz nominal frequency. One of the main advantages of the proposed transformer design is its simple winding system. It contains only two coaxial copper tubes, which can be easily manufactured and modeled with high precision. One of the key design tasks is the minimization of the leakage inductance. The inductance of the straight coils depends on the ratio of the height and the diameter of the coil. Therefore, a three-dimensional FEM analysis is sufficient to calculate the optimal length of the linear transformer. The planar 2D model and the 3D model of the transformer are presented in this paper. The accuracy of the 2D and 3D calculation results were compared to each other and to the measurements to show the applicability of the planar 2D models. Moreover, the sensitivity of the losses and the leakage inductance with respect to the winding parameters is presented. The dependencies of the design variables on the performance parameters, such as the power mass density and the leakage inductance of this transformer concept were examined. It was shown that the value of the leakage inductance is a linear function of the ratio of the length and the diameter of the transformer windings.

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